In semiconductor production, wafers are sequentially processed in a plurality of process steps during the production process. With increasing integration density, demands in terms of the quality of the features configured on the wafers are rising. To allow the quality of the configured features to be checked, and any defects to be found, there is a corresponding requirement in terms of the quality, accuracy, and reproducibility of the components and process steps with which the wafers are handled. This means that in the production of a wafer with the plurality of process steps and the plurality of layers of photoresist or the like that are to be applied, reliable and timely detection of defects in the individual features is particularly important. A plurality of identical repeating pattern elements are provided on a patterned semiconductor substrate or a wafer.
DE 43 10 149 C2 discloses a device for handling disk-shaped objects in a treatment plane of a local clean room. Also provided are magazine receptacles that are adjustable vertically with respect to the treatment plane. Workstations for processing or inspection purposes are located in the treatment plane. The treatment plane is arranged above an intermediate floor that subdivides the clean room into two sub-spaces, located one above another, in which one air flow component of an air flow is directed out of the sub-space above the intermediate floor into the sub-space, containing the drive parts, below the intermediate floor. The air flow prevents any abraded material caused by the drive elements from traveling to the workstations in the treatment plane. The air preparation system comprises a housing, and its air outlet is constituted by a circle-sector-shaped cutout having air-directing panels. Nothing is mentioned regarding the particular orientation, guidance, and/or direction of the air flow within the housing.
German Patent DE 195 38 040 C2 discloses a device for generating a purified turbulent air flow for supplying local clean rooms. The local clean room is surrounded by a housing. The housing possesses an inlet for the air on a side wall. Provided behind the inlet is a radial fan with which air is forced into the inner space of the device. An air outlet is provided on the wall arranged opposite the wall having the inlet. The flow distribution of the air in the interior of the local clean room is not mentioned or taken into account.
European Patent EP 0 335 752 discloses a system for semiconductor manufacture under clean-room conditions. The system comprises a building surrounded by walls, the clean-room conditions existing in a portion of the building. Air is conveyed into the clean room through filters. Holes in the floor of the clean room direct clean air, for example, to another part of the facility. Nothing is disclosed here concerning direction or guidance of the air flow.